Synthesis And Fluorescence Properties Of Novel Phenol-functionalized Terpyridine

2,2':6',2''-Tertiary pyridine compounds have attracted much attention in recent years due to their excellent thermal stability properties.Many compounds containing terpyridine structural units have attracted more and more attention because of its distinctive properties,and are widely used in organic materials,biological analysis and research field of photoelectron,catalysis,sensors and functional materials and others,which increasingly highlighting their important role and potential significance.And especially,2,2':6',2''-tertiary pyridine compounds are increasingly receiving widespread attention from the academic community.Although functionalized terpyridine has gradually become a hot spot in the field of dyes,catalysis and supramolecular,some functionalized terpyridines,such as the introduction of ortho-functionalized groups of nitrogen atoms,remain a challenge,mainly due to the2,2':6',2''-tertiary pyridine compounds rings have extremely high stability,poor reaction activity,chemical selectivity,and separation difficulties?low yields?due to multi-step functional group transformations,so that few studies have reported on the functionalization of 2,2':6',2''-tertiary pyridine compounds in the past decades.In this dissertation,considering no reports of 2,2':6',2''-tertiary pyridine compounds that substituted with ortho-phenoxy groups in the nitrogen atom,we calculated the HOMO-LUMO of the OH-functionalized 2,2':6',2''-tertiary pyridine compounds and proposed it may have characteristic optical and physical properties because of the introduction of phenol groups in this backbone.Accordingly,OH-functionalized 2,2':6',2''-tertiary pyridine compounds is expected to be used as a fluorescent probe.Therefore,on the basis of a series of explorations on the choices of C-H functional group transformations,we successfully developed a new reaction for the synthesis of OH-functionalized 2,2':6',2''-tertiary pyridine compounds that makes it possible to become a new metal ion fluorescent probe.Based on the optimization of various reaction conditions,we found that under a small amount of air,a strong base,t-BuLi,can directly oxidize the 3-position?C?sp2?-H?on terpyridine to a phenol group,thus a novel phenol-containing terpyridine derivative,TpyOHs could be achieved by this oxidation reaction.This synthetic method has a good substrate scope and yield?up to a yield of 83%?for various substituted terpyridine substrates.In addition,the fluorescence properties of the TpyOHs containing phenol groups were investigated in detail,and the AIE?aggregation-induced emission?effect was also evaluated according to classic method.The experimental results show that the pyridine-containing terpyridine derivatives TpyOHs and their analogues have high selectivity for nano-molar?125 nmol?recognition of Zn²⁺,and have obvious AIE effect.In summary,in this dissertation,we successfully synthesized a new type of phenolic functionalized terpyridines,and found that these compounds can be used as high-sensitivity fluorescent molecules for the selective recognition of zinc ions,and found that they have quite strong AIE effect that is expected to be further applied in the field of fluorescence analysis.